1. Field of the Invention
One of a new parent's worst fears is to discover that their newborn had stopped breathing during sleep and died. Despite inadequate explanations for deaths resulting from Sudden Infant Death Syndrome (SIDS), many believe that apnea may be a precursor of SIDS. The standard definition of infancy apnea is cessation of inspiratory gas flow for 20 seconds, or for a shorter period of time if accompanied by bradycardia (heart rate less than 100 beats per minute), cyanosis, or pallor. Although there has been no proven correlation between apnea and Sudden Infant Death Syndrome (SIDS), many parents still demand an in-home device to monitor their newborns and babies as indicated by the availability of infant monitoring systems offered in the market.
Respiration cessations of infants are normal, yet a pause lasting longer than 20 seconds is a cause for alarm. Once 20 second of apnea is exceeded, the baby may begin to turn blue or pale, choke or gag, and go limp. A prolonged apnea that does not result in death is officially called Apparent Life-Threatening Event (ALTE). Infants and babies can be saved if ALTE is detected promptlyi. The mean postmenstrual age for SIDS occurrence is estimated to be 45.8 weeks for infants born at 24 to 28 weeks gestation, compared with 52.3 weeks for full term infants.ii Current evidence suggests that if cardio-respiratory monitoring is elected, it usually may be discontinued after 43 weeks' postmenstrual age although extreme apnea may persist beyond that time in some infants.iii The present invention relates to in-home infant respiration monitoring systems and more specifically to apnea monitoring systems for newborns up to the postmenstrual age of 52 weeks. i Infant Apnea Monitors Help Parents Breath Easy, Dori Stehlin, FDA Consumer Magazine.ii Malloy M H, Hoffman H J. Prematurity, sudden infant death syndrome and age of death. Pediatrics. 1995; 96:464–471iii Apnea, Sudden Infant Death Syndrome, and Home Monitoring; American Academy of Pediatrics, Policy Statements; Organizational Principles to Guide and define the Child Health Care System and/or Improve the Health of All Children, Committee on Fetus and Newborn. Pediatrics. April 2003, Vol. 111 No. 4
2. Description of the Related Art
Devices for in-home infant and baby monitoring range from a simple audio monitoring system to a more complex video monitoring system and to one of the more popular patented methods, the Respiration and Movement Monitoring System (U.S. Pat. No. 6,011,477). This method utilizes “accelerometric” sensors contained in the bedding an infant lies on and detects the infant's movement. It relies on the simple logic that a moving infant is a living infant. This apparatus is intended to monitor movement generated by a breathing infant and alerts caregivers when movement ceases. However, this method does not directly measure the infant's actual breath or lack thereof, but indirectly detects respiration through associated movement. Another similar indirect method, Optical Monitor For Sudden Infant Death Syndrome (U.S. Pat. No. 6,492,634), also monitors the infant's movement using a complex light source in conjunction with an optical device to create a matrix of images. A more precise method for determining infant or newborn respiratory stage should include the detection of the breath itself. The present invention does this that by providing a method and an apparatus for monitoring the humidity resulting from infant respiration.